LOS ANGELES, DEC. 24 -- A fine mist -- formed from a chemical common to lemon and orange juice -- that may be a radically different stop-smoking approach is being readied for a large-scale trial at the University of California, Los Angeles, early next year.

In a newly published study, researchers say that preliminary testing of the mist-inhaler shows that it has promise as a way to substitute the slightly irritating sting of citric acid for the so-called "taste" of tobacco.

And if the early promise is borne out by the larger study, a combination therapy combining nicotine absorbed through the skin from a stick-on patch and puffs on the cigarette-shaped mist inhaler could be an aid to millions of people who are unable to kick their smoking habits now, experts said.

The citric acid mist technique for smoking treatment is described this month in the journal Chest in an article by UCLA tobacco researchers Jed Rose and Carol Hickman. They began working on the theory when they questioned a basic tenet of tobacco treatment theory -- that nicotine alone determines the addiction.

Earlier smoking treatment studies had relied in part on blunting taste-like sensations in smoking -- by such techniques as anesthetizing smokers' throats -- to focus on the chemical action of nicotine. The theory was that tobacco addiction is controlled by the direct effects of nicotine on the brain.

In an interview this week, Rose said he came to suspect that the complex sensations that are lumped together in what is commonly called tobacco "taste" may play more of a role in some people than does the chemical action of nicotine.

The craving for the taste gratification of smoking is not satisfied by simply sucking lollipops since the sensations in the mouth, throat and lungs of inhaling smoke still lack.

To test the theory, Rose and Hickman developed a fine mist of citric acid that is inhaled by smokers and that mimics the irritation capability and taste components of tobacco smoke. With their olfactory senses artificially blocked -- so they could not smell the difference between tobacco and the lemon-like odor of citric acid -- 15 smokers reported that they found citric acid somewhat less satisfying than their favorite brands of cigarettes but more satisfying than low-tar cigarette brands they also smoked for the study.